1. Field of the Invention
The invention relates to apparatus for anchoring equipment to supporting surfaces, and more particularly, to anchor bolts which can be extended through a hole in the supporting surface to engage a joist or rafter which holds the supporting surface on which the equipment is to be mounted.
2. Description of the Prior Art
Frequently it is necessary to install massive units, such as air conditioners, solar collectors, parabolic antennas, and the like on roofs of pre-existing residential and/or commercial buildings. Since very high winds occasionally occur in practically all localities, it is obviously necessary that such equipment be very securely anchored to a roof upon which it is installed. Ordinarily, the anchoring means must be attached in some manner to the rafters or joists (hereinafter referred to as "beams") supporting the roof. One approach to attaching mounting brackets associated with equipment to be installed on a roof is to screw threaded lag bolts through the roof covering and sheathing into the supporting beams. However, this approach tends to weaken the beams somewhat. Further, lag bolts have a tendency to gradually become loosened as a result of local temperature and humidity variations and the cumulative effect of repetitive wind forces on the installed equipment. Once a lag bolt becomes loosened, it can be easily torn loose from the beam. Various other devices have been utilized to anchor equipment to roofs. One such device is a J-bolt having a shank threaded at one end and a hook at the opposite end. The threaded end of the shank of the J-bolt is commonly inserted from the underside of a roof through a hole in the roof adjacent a supporting beam. The hooked end of the J-bolt is looped beneath the supporting beam by a worker in the attic of the building. Meanwhile, a worker on top of the roof ensures that the threaded end of the shank passes through a hole or notch in a mounting bracket for supporting the equipment and places a washer and a nut on the threaded end. The nut is then tightened so that the hooked end of the J-bolt is drawn tightly against the underside of the supporting beam, thereby producing a counter-force on the nut, drawing the mounting bracket tightly against the roof surface. The necessity of inserting the threaded ends of the prior J-bolts from the under side of the roof through the holes therein is a time consuming and costly inconvenience, especially in flat roofed buildings of the type which have no attic (such flat roofed buildings are common in the Southwestern part of the United States). Thus, there is an unmet need for a convenient means of securely anchoring equipment on roofs of buildings.
Accordingly, it is an object of the invention to provide a convenient means of anchoring equipment to the roof of a building without the necessity of having a worker insert bolts from the underside of the roof through holes in the roof.
Another object of the invention is to provide an anchor for anchoring equipment to the roof of a building without weakening joists or rafters supporting the roof.
Still another object of the invention is to provide a means of anchoring equipment to the roof of a building by engaging joists and rafters which does not weaken as a result of repetitive weather variations.